CrystalImageHandler.aspx not found

I had the same problem, but fortunately I have some experience with Crystal Reports.

You just need to change the Web.config, because the "path" attribute is set to site root. It will work if you open the url in browser and remove the ReportWebForms from it.

Actually I've just added 2 more lines of configuration:

<system.web>
    <httpHandlers>
      <add verb="GET" path="CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" />
      <!-- Added -->
      <add verb="GET" path="Reports/CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" />
      <add verb="GET,HEAD" path="asset.axd" validate="false" type="Telerik.Web.Mvc.WebAssetHttpHandler, Telerik.Web.Mvc" />
    </httpHandlers>
</system.web>

<system.webServer>
    <handlers>
      <add name="MiniProfiler" path="mini-profiler-resources/*" verb="*" type="System.Web.Routing.UrlRoutingModule" resourceType="Unspecified" preCondition="integratedMode" />
      <add name="CrystalImageHandler.aspx_GET" verb="GET" path="CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" preCondition="integratedMode" />
      <!-- Added -->
      <add name="CrystalImageHandler.aspx_GETR" verb="GET" path="Reports/CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" preCondition="integratedMode" />
      <remove name="asset" />
      <add name="asset" preCondition="integratedMode" verb="GET,HEAD" path="asset.axd" type="Telerik.Web.Mvc.WebAssetHttpHandler, Telerik.Web.Mvc" />
    </handlers>
</system.webServer>

And finally you have to add an ignore rule the route for MVC application:

routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.IgnoreRoute("{resource}.aspx/{*pathInfo}");
// Here is added new ignore rule
routes.IgnoreRoute("Reports/{resource}.aspx/{*pathInfo}");

In my case I have a folder named Reports where the .aspx file is placed. I guess you should change this to ReportWebForms in your case.

In my case I only had to ignore MVC's routing.To add onto @Hovhannes solution.You should add this rule to Routeconfig.cs

routes.IgnoreRoute("{*allaspx}", new { allaspx = @".*(CrystalImageHandler).*" });

Use this code as CrystalImageHandler.aspx:

<%@ Page Language="C#" AutoEventWireup="true" %>

<script runat="server" language="c#" >
    protected void Page_Load(object sender, EventArgs e)
    {
        CrystalDecisions.Web.CrystalImageHandler handler = new CrystalDecisions.Web.CrystalImageHandler();
        handler.ProcessRequest(this.Context);            
    }
</script>